> For the complete documentation index, see [llms.txt](https://nxp.gitbook.io/mr-canhubk344/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://nxp.gitbook.io/mr-canhubk344/hardware/connectors-and-user-i-o/power-input.md).

# Power Input

Power is normally applied at the 5-pin JST-GH connector P27. Alternatively, power may be supplied at the two-pin header P28 located directly below P27.

## Power Input Connectors

#### Connector P27:

<table><thead><tr><th width="90">Pin #</th><th width="144.33333333333331">Signal</th><th>Specification</th></tr></thead><tbody><tr><td>1</td><td>Power+</td><td>+5 to +40V</td></tr><tr><td>2</td><td>Power+</td><td>+5 to +40V</td></tr><tr><td>3</td><td>NC</td><td>NC</td></tr><tr><td>4</td><td>Power- (GND)</td><td>0V (GND)</td></tr><tr><td>5</td><td>Power- (GND)</td><td>0V (GND)</td></tr></tbody></table>

#### Header P28:

This is a 2 pin 0.100" header that can be used to hardwire or provide power in another way or  with a wire mount connector.

{% hint style="danger" %}
PLEASE DOUBLE CHECK the polarity when using P28. Use a multimeter to confirm against the pins on P27. \
Some boards have a "+" sign for the capacitor in a location that can be misleading!!!!
{% endhint %}

<table><thead><tr><th width="92">Pin #</th><th width="142.33333333333331">Signal</th><th>Specification</th></tr></thead><tbody><tr><td>1</td><td>Power+</td><td>+5 to +40V</td></tr><tr><td>2</td><td>Power- (GND)</td><td>0V (GND)</td></tr></tbody></table>

<figure><img src="/files/66BuhEH1M9FHuCgaNSd2" alt="" width="563"><figcaption><p>Power input connectors P27, P28 schematic</p></figcaption></figure>